Power spectral entropy of acoustic emission signal as a new damage indicator to identify the operating regime of strain hardening cementitious composites

Abstract

For strain-hardening cementitious composites (SHCCs) the knowledge of operating regime is important for maintenance planning and monitoring of the element. This paper presents a methodology of regime discrimination for SHCC from acoustic emission (AE) signals. From an AE signal, various damage indicators (DIs) can be derived. A new DI called Power Spectral Entropy (PSE) is developed in this paper. New benchmarks are developed to quantify possible effect of external factors on the measurement accuracy. Theoretical results indicate that the PSE is Signal to Noise Ratio (SNR) invariant, insensitive to the choice of subjective parameters and can be performed in real time. PSE was then obtained from the test result of SHCC with elastic behavior followed by strain hardening and softening. The test results indicate that the PSE varies with strain in a very similar way to the applied load. An approach to distinguish between different operating regimes of a SHCC component based on PSE is then proposed and validated. The practical applicability of PSE is hence demonstrated.